Water-soluble polyethylene glycol polyesters curable to insoluble polymers



United States p O Y 2,914,509 WATER-SOLUBLE POLYETHYLENE GLYCOL POLYESTERS CURABLE TO INSOLUBLE POLYMERS 2,914,509 Patented Nov. 24, 1959 The polyethylene glycols comprise a; series of homologous polyols which gradually increase in molecular weight according to the number of CH -CH -O- units contained in the molecule. They are generally and Howard C. Woodrulr, Latham, N.Y., assignor to General 5 conveniently designated by placing in Arabic numbers Electric Company, a corporation of New York their approximate molecular weight after the name poly- No Drawing. Application December 28, 1953 ethylene glycol. For instance, polyethylene glycol 300 Serial No. 400,755 corresponds to H(C H O) H and polyethylene glycol 12 Claims. (Cl. 260-75) 600 corresponds to HO(C H O) H. This invention relates to new compositions and their other methods 9 F l the f l 9 l of preparation and more particularly to new storage-stable i type.under cpnslderauon gel or have water-soluble polyesters which can be converted to new resulted. re.sort,mg to a substmitlon of m -3' water-insoluble polymers which are free of surface tack. P p mgredlents: For, ample 1t hasbee? found h Bra d1 ey 2,166,542 teaches that polyesters made with it is possible to replace a part of the maleic anhydride polyglycols, for example polyethylene glycol 'maleate, are 15 qi fi f g g g h p f g q 609dma1eate water-soluble, and that these polyesters can be converted W1 a Sa ura e l aslc sue a IP16 am or one to a gel by means of heat, or alternatively by the mech- F not have. Raddy P1ymenZab1e.dul?1e bonqs anism of free radical catalysis, or by means of oxygen. ivallabledfort gi ifi g as g g I Polyesters of this type, for example the polyethylene gly- 20 J f 1 I re ucg t i col maleates, form a substantially water-insoluble corii on s 9 g figf re am a aceous mass upon curing, whereas polyesters derived from sur ace er 0 an m 6 mass t e monomeric glycols cure with a tacky surface. The polyfina1.prduct 1S slmllar. that. as ethylene glyc o1 maleates for example, cure in a mass previously by the addition of inhibitors or stabilizing f b agents. V 322225 53: ggg g g g zg g g giggf f g $35 It has now been found that water-soluble polyesters curing are of considerable advantage in applications where be prepared whlch can be caused cure to a watFrit is necessary for the polyester to cure in a thin film in Insoluble mass free of surfaw i 5 polyesters bemg the Presence of air H Owev er a polyester su'ch as the stable on storage before curing is desired in the presence polyethylene glycol 400 maleate possesses, additionally, of ani q mammals In accord a very serious disadvantage which limits, and i many 3 31106 th thls lllventlOfl lt has been found that polycases presents a situation in which its use is impossible. g f i g maletqtes f f g can prteparefi This undesirable property, or major disadvantage, is that u m w c a per Ion o e reac.lve unsa ura Ion is of continuing conversion which refers to the tendency removed from the i i cha1n.f.rmmg structure of of polyethylene glycol maleates for example to conpolyester. reactmg m aiddmon to.the ethylenq tinue to react to c of thenlsalves on stoiage and 'carboxylic acid such as maleic or fumaric, an unsaturated after a few da S to Chan 6 from medium viscosity liquids dicarboxylic acid in which the unsaturation is removed to gels The tgndency togconvert or a even under from the direct chain of atoms connecting the carbons normal conditions ofstorage is not subject to any method fS M d of control heretofore known to the art without resorting e resu tmg p0 yesters am 6 urmg Storage m 40 the presence of oxygen and on curing become tough and to control agents or inhibitors which render the product I unsuitable for Subsequent use For example when c oriaceous, and retain the1r lability to form tack-free or droquinone is used as a stabilizing agent, the surface cure dry g exaglp It f F characteristics of the polyester is so altered that tacky pecte y t at Po yesters enved t estenficauo. cure products are formed. Various other stabilizing" of poliiethylene. glycffls i combmanon of m agents such as butyl catechol were also found to have the anhydnde ltacomc acld are staplepn storage m same effect, namely, that instead of the cured polyester pr-eSe1.1 :e of andlwhoen cured. the Pmsence of a having a surface which under ordinary conditions of air peroxlde catalyst Tapld y form tough tack o tack the surface was rendered tack by free masses. Additionally, it has been found that the 2 5 35:3 3 e ofythese agents y same desirable characteristics are also exhibited by poly- The combined characteristics of these soluble poly- 50 esiers denved p polyeihylene f estenfied with a esters namely curing to a non-tacky surface, combined fi g g i i fi g g fg f a yg g g r tmgte -acianyrieprouce blt ,were observed In a series of 01 a y n e .eslgna th yilzii gi yh l nia lgates and fumarates These ies t s 9; ndensng i aIh-ydnde g cyclopfimgdlene' e pro nets 0 talne 1n accor ance wit t e process showed that both malelc and fumaric acid derivatives of of this invention are watfipsoluble and cure in the Poll/glycols cohtalmng. from 5 to 11 ether hnkages form presence of peroxide catalysts or free radical catalysts HOIHaCKY masses When cured, but that the polyestfifs or heat, to cured products which are substantially waterth el s were unstable 011 stol'age- The followlhg insoluble. The uncured products on storage in the prestable summarizes a series of tests in which the molecular ence of air maintain an unchanged structure. Specificalweight of the glycol is expressed numerically: 6O 'ly, they remain essentially unchanged in viscosity and No. of Storage Ethylene Water- Type of Stability Alcohol Tgilycoiln Acid Solubility sirface inPfreAssure 111 S Polyglycol me 0 1r Polygthylene Glycol 300.- g ljvialeic n Soluble-" Non tacky" Uilijstable umar1c 0 O. Polyei hylene Glycol 600 5 Maleic Do. D 5 Fumanc d Do. 7 Maleic d do Do. 7 Fumaric do do Do.

do not form a skin on the surface. After three months" storage, for example, they are unchanged in appearance and physical characteristics, the products are still soluble in water, and upon curing form non-tacky homogeneous 'products comparablefin every 'way to similar cured derivatives produced from the freshly'prepared polyester. border that those skilledin the art may better understand how the present invention may be practiced, the

following examples are given by way of illustration-and not by way of limitation. All parts are by weight.

Example 1 v In a flask equipped with an agitator and a Dean- Stark type reflux, were mixed 600 parts of polyethylene glycol 600, 80 parts of fumar'ic acid, 46.8 parts of carbic anhydride and 80 parts of xylol. Under reflux, xylol was returned to the flask and entrained water was separated at a refluxing temperature of about l60l70 C. When all the water was separated, a stream of inert gas was passed through the mass and the condenser removed. The reaction system was thus freed of xylol, and consisted of an odorless polyester which was allowed to cool and was stored. This polyester had the following characteristics:

Color 6-7. Viscosity Z Acid value 24.

Cure time (200 C.) 3 seconds.

Water solubility Complete.

Storage stability No change after 3 months.

Cure (1% tertiary butyl per phthalate added to resin before curing grams resin cured at 150 C.)very tough tack-free cure.

Example 2 In a manner similar to that described in Example 1, itaconic acid and furnaric acid resin were prepared by mixing 900 parts of polyethylene glycol 600, 120 parts of fumaric acid, 58.5 parts of itaconic acid and 30 parts of xylol. After the reaction was carried out in a manner like that of Example 1, the characteristics of the polyester produced were:

Viscosity Z-4.

A'cid value 20.4.

Color 9.

Cure (200 'C.) 2 seconds.

Mass cure (1% tertiary butyl per phthalate added to resin before curing) (10 grams resin cured at 150 C.) very tough tack-free cure. Storage stability- No change after 3 months. Water-solubility Complete.

The differences in structure between the storage stable products produced as above in Examples 1 and 2 from other polyethylene glycol unsaturated polyesters are shown in the following formulae in which A represents a structure wherein all active unsaturation is an integral link in the chain structure of the polyester. Structures B and C illustrate polyesters wherein only a part of the active unsaturation functions as links in the polyester chain structure. The remaining double bonds designated as N do not form part of the chain structure. chain structure of the polyester) points to unsaturated bonds not in the direct 95% of the total unsaturation.

4 saturate reactive groups are in the polyester chain structure.

t a t O(C:H5O) 2?-C::-O(C:H50)12 ?=?-C Hg H H polyethylene glycol .600 itaconate-maleate showing how a portion of the active unsaturation is removed from the chain structure of the polyester.

0 0 lI II U II -O(C:H5O)l2-' GC-C0(O7H50)1:CC=CC H H HC-C=CCH u C 2 n polyethylene glycol 600 carbate-maleate showing how a portion of the active unsaturation is removed from the chain structure.

In the above formulae, A is representive of a structure that:

(1) is water-soluble '(2) cures in the presence of (a) peroxide catalysts (b) free radical catalysts (c) heat (3) the cured products are substantially water-insoluble (4) on storage in the presence of air rapidly increases in viscosity, forms a gel structure and skins over the surface (5) the gel structure is not soluble in water. However, on curing it forms a tacky non-homogeneous product and is not suitable for application in thin films.

Structures Band C are illustrative of compounds having the following highly desired properties:

It is apparent that one skilled in'the art, from examination of the structural configurations exhibited by each of formulae A through C respectively, could not predict 'the excellent storage stability of B and C and their ability to yield non-tacky cured films. It has been found, however, that certainlimits of ratio between polyester chain type double bonds and non-chain double bonds are necessary to produce these desirable characteristics. If all of the double bonds arenon-chain type, the structure will not cure to a tough and tack-free mass. If insufficient non-chain double bonds are present, the structure will be sensitive to oxygen under storage conditions and be unstable. Accordingly, it has been found that the necessary ratio of non-chain double bonds to chain double bonds is between 5 and 40% and is preferably in the range of 25 to 35%. This means that the direct ester-to-ester unsaturation represents between 60 and These values may be obtained by employing an acid having unsaturation removed from the direct chain of the carboxyl-to-carboxyl linkage in the mol ratio of from 0.25 to 0.45 mol based on the acid having chain unsaturation. For example, these values may be obtained by employing from about 0.25 to .45 mol of an acid, such as itaconic or carbic acids, per mol of an acid such as maleic or fumaric or maleic anhydride. When employing the foregoing ratios of acid, the proportion of polyhydric alcohol which may be used lies in the range of 1 mol of alcohol to .7 to 1.4 mols of combined acids.

Further unobviousness of the properties of the polyesters prepared in the manner of the present invention can be demonstrated by the observation that mixtures of polyethylene glycol 600 maleate with polyethylene glycol 600 carbate do not have the characteristics of polyethylene glycol 600-carbatemaleate polyester prepared by processing together in a unit synthesis or single step operation, polyethylene glycol 600, maleic acid (or fuman'c acid) and carbic anhydride. It has been observed that the mixed products invariably retain a surface tackiness, the surface tackiness not being found in' the cured products prepared by processing the ingredients together.

The process of this invention is not limited to itaconic acid or carbic anhydride but has broader application to related acids.

The novel products of this invention have a wide field of utility. They may be used in textile or in paper manufacture where it is desired to deposit or coat a material with a synthetic resin from a water solution which is capable of air curing to a non-tacky surface. They may be used as binders for glass wool fibres in the manufacture of insulating bats. Other applications include use as sizing materials, as binders for abrasive, in the manufacture of laminates, etc.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. The method of producing a water-soluble unsaturated polyester in which unsaturation directly in the ester-to-ester chain structure represents between 60 and 95% of the total unsaturation, and unsaturation other than directly in the ester-to-ester chain structure represents between 5 and 40% of the total unsaturation, which comprises the one-step process of esterifying at an elevated temperature about one mol of a polyethylene glycol having a molecular weight between 300 and 600 with about 0.7 to 1.4 moles of (l) a member selected from the group consisting of ethylenically unsaturated dicarboxylic acids and their anhydrides, the unsaturation being present in the chain of carbon atoms connecting the carboxyl groups, and (2) a member selected from the group consisting of itaconic and carbic acids and their anhydrides, the mol ratio of the second group member being between about .25 to .45 mol per mol of the member selected from the first group.

2. The water-soluble polyesters produced in accordance with the process of claim 1.

3. The stable insoluble product obtained by heat-curing at a temperature of the order of 200 C. the product produced in accordance with the process of claim 1 in the presence of tertiary butyl perphthalate as catalyst.

4. The method of producing water-soluble polyesters in which the percentage of total unsaturation of nonchain double bonds is between 25 and 35% which com prises esterifying at an elevated temperature about one mol of a polyethylene glycol having a. molecular weight of between 300 and 600 with about 0.7 to 1.4 moles of (l) a member selected from the group consisting of ethylenically unsaturated dicarboxylic acids and their anhydrides, the unsaturation being present in the chain of carbon atoms connecting the carboxyl group, and (2) a member selected from the group consisting of itaconic and carbic acids and their anhydrides, the mol ratio of the second group member being between .25 and .45 mol per mol of the member selected from the first group.

5. The water-soluble polyesters produced in accordance with the process of claim 4.

6. The stable insoluble product obtained by heat-curing at a temperature of the order of 200 C. the product produced in accordance with the process of claim 4 in the presence of tertiary butyl perphthalate as catalyst.

7. The method of producing water-soluble polyesters in which the percentage of total unsaturation of non-chain double bonds is between 25 and 35%, which comprises esterifying at an elevated temperature about one mol of a polyethylene glycol having an average molecular weight of 600 with about 0.7 to 1.4 moles of (l) maleic acid and (2) itaconic acid, the itaconic acid being employed in an amount corresponding to .25 to .45 mol per mol of maleic acid.

8. The water-soluble polyester produced in accordance with the process of claim 7.

9. The stable insoluble product obtained by heat-curing at a temperature of the order of 200 C. the product produced in accordance with the process of claim 7 in the presence of tertiary butyl perphthalate as catalyst.

10. The method of producing water-soluble polyesters in which the percentage of total unsaturation of nonchain double bonds is between 5 and 40% which comprises esterifying at an elevated temperature about one mol of a polyethylene glycol having an average molecular weight of 600 with about 0.7 to 1.4 moles of (l) fumaric acid and (2) carbic anhydride, the carbic :anhydride being employed in an amount corresponding to .25 to .45 mol per mol of fumaric acid.

11. The water-soluble polyester produced in accordance with the process of claim 10.

12. The stable insoluble product obtained by heatcuring at a temperature of the order of 200 C. the product produced in accordance with the process of claim 10 i in the presence of tertiary butyl perphthalate as catalyst.

References Cited in the file of this patent UNITED STATES PATENTS 2,166,542 Bradley July 18, 1939 2,308,494 DAlelio Jan. 19, 1943 2,475,731 Weith July 12, 1949 

1. THE METHOD OF PRODUCING A WATER-SOLUBLE UNSATURATED POLYESTER IN WHICH UNSATURATION DIRECTLY IN THE ESTER-TO-ESTER CHAIN STRUCTURE REPRESENTS BETWEEN 60 AND 95% OF THE TOTAL UNSATURATION, AND UNSATURATION OTHER THAN DIRECTLY IN THE ESTER-TO-ESTER CHAIN STRUCTURE REPRESENTS BETWEEN 5 AND 40% OF THE TOTAL UNSATURATION, WHICH COMPRISES THE ONE-STEP PROCESS OF ESTERIFYING AT AN ELEVATED TEMPERATURE ABOUT ONE MOL OF A POLYETHYLENE GLYCOL HAVING A MOLECULAR WEIGHT BETWEEN 300 AND 600 WITH ABOUT 0.7 TO 1.4 MOLES OF (1) A MEMBER SELECTED FROM THE GROUP CONSISTING OF ETHYLENICALLY UNSATURATED DICARBOXYLIC ACIDS AND THEIR ANHYDRIDES, THE UNSATURATION BEING PRESENT IN THE CHAIN OF CARBON ATOMS CONNECTING THE CARBOXYL GROUPS, AND (2) A MEMBER SELECTED FROM THE GROUP CONSISTING OF ITACONIC AND CARBIC ACIDS AND THEIR ANHYDRIDES, THE MOL RATIO OF THE SECOND GROUP MEMBER BEING BETWEEN ABOUT .25 TO .45 MOL PER MOL OF THE MEMBER SELECTED FROM THE FIRST GROUP. 